


Whatever You Need

by ninchannie



Category: Stray Kids (Band)
Genre: Consensual Sex, Creampie, Demon Kim Seungmin, Demon Sex, F/M, Face-Sitting, Female Hyunjin, Hetero Sex, Knotting, Multi, Oral Sex, Porn With Plot, Succubus, Succubus Seungmin, Vaginal Sex, a very sweet ending, friendship sex, gaping, hyunjin is a really pretty girl in this one, hyunjin is kinky, i dont know how to tag please just read it, my own kind of succubus lore, pillow princess hyunjin, seungmin can change his genitals to everything
Language: English
Status: Completed
Published: 2020-01-12
Updated: 2020-01-12
Packaged: 2021-02-27 13:08:53
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 15,391
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22227667
Author URL: https://archiveofourown.org/users/ninchannie/pseuds/ninchannie
Summary: “Let me get my facts straight: First you have a dick, now you have a vagina and you tell me you’re a succubus. From what I see there are a few possibilities of what is going on.”, Hyunjin places the cup down in front of her and Seungmin notices the way her fingers shake around it. “Either I am having a crazily realistic dream, you’re pulling a very intricate prank on me, or I’m going crazy and am already so high on drugs that I don’t know what reality is anymore.”“Have you considered that the easiest answer might be the right one?” Seungmin doesn’t mean to sound a cryptic as he does, and he cringes after the sentence leaves his lips. Hyunjin finally smiles, chuckling in that beautiful way of hers that lights up Seungmin’s whole world.“So the dream one?” She asks, seeming a tiny bit relieved but in the way her eyes keep flickering from one point on Seungmin’s face to the other, the demon knows she doesn’t quite convince herself.“That this is all real and you’re just learning something new about the world and the people in it.”orHyunjin has given up on a satisfactory sex life but finding out her best friend is a succubus might be able to change that.
Relationships: Hwang Hyunjin/Kim Seungmin
Comments: 12
Kudos: 158





	Whatever You Need

**Author's Note:**

> Hello,
> 
> thank you so much for being here and reading this very paticular fic.  
> It was actually really challenging to write straight sex, but I hope I managed to do it in a fashion that isn't cringy or awkward to read.  
> I had this idea during Hyunjin thristy hours, because I just imagined him with long, curly black hair and in pretty dresses and then I thought what if I switch it up and have Seungmin be the demon for once, so yes. It has come to this. 
> 
> I hope you'll enjoy it and thank you so much for reading!
> 
> ~N

At some point between the age of nineteen and twenty-five life gets boring. You have found your small circle of good friends, somehow manage to keep up with your family and learn to balance work or uni alongside the tiny string of free time you grant yourself.

Hyunjin doesn’t know at what point exactly her life has become _this_ boring. Right now, she is happily skipping up the stairs to her apartment, because her learn group cancelled on her. In her first semester she would have been equally excited, but not for getting home two hours earlier, no, she would’ve rung up her friends to meet up in the city. Go shopping or to the gym, party at a club and actually get drunk without horrendous headaches the morning after.

This time, she can’t wait to get home, run herself a steaming bath, shave her legs and then cuddle into bed for a few hours, maybe even splurging and ordering herself pizza. Hell, maybe she will even clean the kitchen whilst listening to old boyband albums, not bothering her roommate, who she knows will be out until late. A usual Thursday for him.

She shakes the thought of having become one of the adults she used to make fun of in school away as she fumbles for her keys. Boring doesn’t have to be bad after all. It means safety and warmth, people she can depend on and a lot of time to care for herself. Sure, it can be less exciting than going on random adventures like she used to, but her bed is just that much more comfortable than a tent or a random couch.

Well, comfortable it might be, but most evenings it feels cold too. Cold and lonely and stale. Like many things in Hyunjin's life. The cheap coffee she brews herself every morning or the same old pasta recipe she keeps cooking for herself. The same music she listens to while dancing through her room, wearing her same old clothes that keep getting more and more bleached out from sun and wash after wash after wash.

The way sex feels lacklustre and tiring. Oh, how she misses the times she felt fulfilled and content at the hands of her lovers. Nowadays she would much rather do it herself than hope for a good catch, that will inevitably disappoint her anyway. Yes, at some point life gets boring.

With a sigh, she opens the door, wondering how her brain can jump from happiness at going home early, to dread of her existence in the blink of an eye. Shutting the door behind her, she slips off her shoes and throws her backpack to the side, Seungmin won’t be there until later to scold her for it, there will be time to clean up her mess. If she remembers at least.

Hyunjin probably should notice how Seungmin's keys are laying in the bowl next to where she is placing hers. Or how the windows are opened to let in the last breathes of summer air as she turns to close them, wanting to be comfy and warm. You don’t leave windows open when you go out.

Her mind seems to be more preoccupied with random thoughts of what to eat later, what movie she’ll watch, that she should probably clean her dildo if she plans to use it later. Whatever thoughts there are, they are apparently too loud to alert her of the footsteps echoing from the hallway into the living room, the slap of naked skin on cold tiles.

She only truly realizes, when it’s already too late and Seungmin is in the middle of the room, his hair damp from a shower and only a towel hiding his private parts. He realizes it then too, stopping in his step because he probably should’ve noticed Hyunjin sooner as well, his citrusy shower gel obviously numbing his nerves. He motions to cover up then, reaching to hide his chest despite no need to do so and in the midst of fumbling and yelping in surprise-

The towel drops.

With a finite pillowy thud it lands in a bunch around his ankles, the effort to cover up made useless because Seungmin might have his chest covered now, but he has something else fly free at the price of it.

Something else that _should_ be a dick. A cock, a penis, something phallic definitely, because Hyunjin has _seen_ it before. Has stumbled in on Seungmin in a similar situation, a deja-vu of walking in on him naked. _But that time he had a dick_.

Now, where normally something would swing between Seungmin’s thighs, soft and cute and _there_ , is nothing. Not the smallest hint of balls or a penis or anything similar to speak of. The thing that Hyunjin _can_ see is something a lot more familiar. Something she sees in the mirror every day. That soft curve inward from both sides, clean shaved and there’s no mistaking it. You can hide a penis of course, bend it back and tape it down but there is no way it would look like _this_. Soft lips parting ever so slightly around a clitoris and what lays beyond.

“H-Hyunjin...” It’s a quiet stuttering sound, enough in the heavy air to make both of their ears ring. Seungmin lets his hands fall to the side, no need to hide himself when Hyunjin has seen everything anyway. He debates for a second to grow himself a penis and try to explain this, but how would he? Telling his roommate he put hallucinating drugs in her morning coffee and now she can’t see the difference between a vagina and a penis? Doable, but Hyunjin would never fall for it, of course not.

She is neither blind nor stupid after all, awake and rational more than anyone else and it dawns on Seungmin that he won’t be able to explain this one. That he will have to leave this town too and try find footing somewhere else. That he will have to report to the Council and hope he won’t get thrown back into the depths of hell for revealing himself to a human.

“Seungmin?” It’s a question, for nothing and everything at once, for _something_. Because Hyunjin wants to understand, is ready to understand. She doesn’t care if Seungmin had some kind of surgery down there, doesn’t even care for the reasoning behind it, but she wants to know _how_. Because she isn’t in her last master’s semester of queer studies to not know how reassignment surgery works. She knows how it’s done and how it looks after. And this just isn’t it.

Especially not in such a short time. If Seungmin would’ve had the surgery he would have needed months of recovery, months of pain and healing and it still wouldn’t look like _this_. They’ve known each other for a bit over a year, Hyunjin has seen Seungmin’s dick maybe a few months ago, there is just _no way_ that he could’ve had the surgery and healed too perfectly in such short time.

“Hyunjin I-" _can’t explain_. Seungmin can’t after all. He feels his throat tighten and the heart of his human body beat quickly, too quickly, in his chest. He just lost the life he had been building so carefully for the last few years. Even for a being like him, where a few years feel like nothing in the grand scheme of life, the last years finally felt _real._ Like he finally found a place in a world that isn’t his.

And now he’ll lose it because he couldn’t keep it in his pants. Quite literally.

He expected to have a slip up like this at some point. That a human will pick up on his otherworldly body or the way he tastes like their favourite food instead of sperm. He expected it however, to be during sex or during seducing someone. Not with his roommate, _his best friend_ , walking in on him and seeing his pussy.

He could’ve been careful and just always have a dick out at home. But dicks and pants don’t go together at all in this world. It actually hurts if you sit weirdly, or the fabric is too stiff, and _a vagina is just there_. Sure, it would be easier to have nothing at all, but in his human form he needs to go to the toilet too and always growing a vagina or penis just for that purpose would be one hell of a lot of wasted energy he would have to find someone to feast on for.

So, a vagina it is. Not only for comfort reasons of course, Seungmin just adores the feeling of it. A succubus might feast off of the pleasure of other beings, but that doesn’t mean they can’t enjoy themselves too. It probably feels similarly orgasmic to what humans feel, given they don’t only taste the satisfaction of getting energised, but also the high any other human would feel, since that is the body they use for it. It has a beating heart, blood running through it, and the same feelings accompanying it like a human.

Seungmin definitely likes the feeling of a clit when he’s on his own. It is frowned upon under demons, to touch yourself when there are so many humans you could do it with. But Seungmin has never been like other demons. Much like this situation shows.

“Seungmin,”, Hyunjin’s tone doesn’t allow a response, so the demon stays quiet. “where the fuck is your dick?”

She wished she would’ve worded it differently, be more respectful of whatever is happening, but the pure shock of standing in the same room as a naked Seungmin is making it hard for Hyunjin to form coherent thoughts. The _nakedness_ of Seungmin, is probably what makes it so hard. 

“I, _uh_ , yeah about that... well...” even hundreds of years in and out of hell haven’t prepared Seungmin for this. For _the talk_ like no other. Because how in the hell would you describe being a demon straight from hell to a human who doesn’t believe in anything of that sort.

Thankfully Hyunjin seems way too preoccupied spinning her own theories to even give Seungmin time to explain. “Surgery? But _how_?” And suddenly she is stalking towards the demon dropping to her knees and the surprise of finding her roommate with a vagina must have fried the chords making her brain work because she is kneeling right in front of Seungmin’s crotch, head cocked to the side to get a better look. _Yup, that’s a vagina._

Seungmin can’t hold back a panicked laugh at that, because it’s just so _human_ to come to that conclusion. For a second, he thinks about rolling with it, trying to somehow make it plausible, but Hyunjin is an _expert_ at the topic, one of her studies main focuses being SRS and how it affects individuals. She wouldn’t buy it for longer than a day.

_A day that could give Seungmin enough time to disappear._

It hurts to even think into that direction, because even on her knees in front of Seungmin’s groin Hyunjin is still his friend. His best friend to be precise, having quickly grown so attached and close to each other after Seungmin moved in. If anyone could understand it would be her, right? So maybe it’s worth a shot. It can’t possibly get worse after all. And if it somehow does, the Council will just send a higher demon to erase Hyunjin’s memory and torture Seungmin for all eternity in the deepest corners of hell. So, no risks at all.

Swallowing down the dread of his impending doom, Seungmin somehow manages to collect himself and slumps down to his knees too, now face to face with his friend. The tiles are cold against his bare knees but how could he care with much more important things to figure out?

“Jinnie...”, he begins, hurting at the thought that this might be his last chance to use the nickname. Once more Seungmin pushes down every worry clouding his mind. “Did you ever hear of the term succubus?”, because history might be wrong about them in many aspects, but there is some truth in the tales and legends, that Seungmin hopes will help Hyunjin understand. “Surprise I guess...”

Trying to lighten the situation does not seem to go well when Hyunjin doesn’t chuckle at Seungmin’s remark, only her brows furrowing as if in deep, deep thought.

Hyunjin should probably scream or laugh or _cry_ , do something other than just sit there and think for what feels like an eternity to Seungmin. She probably should do one of those things when her best friend tells her that he’s some kind of non-human being, but apparently her brain thinks it’s more important to rummage through her very limited knowledge of sex demons, acquired mostly through random late-night searches on _urbandictionary_ and bad porn.

“You mean an incubus?” In no world would the statement lighten the implication of Seungmin being a _demon_ , but weirdly enough it’s the only thing coming to Hyunjin’s mind.

Because as she remembers succubae are portrayed as full-breasted women stealing semen of men in their sleep and for what she knows Seungmin does not fit that descriptor very well at all. Incubi however fit more to his picture, men with a devilish beauty impregnating women. Hyunjin would count Seungmin’s beauty more on the _angelic_ side, but alas she is still in shock, not many of her recent thoughts seem to make sense.

It is in no way an exaggeration to say that Seungmin nearly topples over at the words, gags rippling through him as he exaggeratedly acts like he is going to be sick. Hyunjin looks up at his face at that, confusion even more prominent on her features.

“Excuse you?”, Seungmin sounds beyond offended, his voice high and disbelieving. “Don’t compare me to those rapists. I’m a _succubus_ , I can’t impregnate people, which is what those fuckers live for. _Yuck_ , Hyunjin, seriously _ew_!”

Hyunjin looks at him in a way that just screams _help_. She understands the words, hears him clearly, but the way he is talking about the topic like it’s nothing is just unfathomable for her. But then maybe that’s the thing, in his world this is normal, it truly _is_ nothing. And maybe this is a weird dream that she will wake up from any second, but Hyunjin preaches about tolerance and respect on her blog and in her essays every day, she can’t deny Seungmin that same right.

On stumbling legs Hyunjin stands up then, straightening her clothes before looking down at Seungmin. She looks away in a split second because her roommate is still naked and she wants to give him a chance to truly explain, but _that_ is not making it any easier. Also, she needs a second to herself before Seungmin can even begin to tell her more, because Hyunjin feels like she might faint any second.

“I...”, her voice is trembling too. “Just put some clothes on. I’ll be right back.” And with that she storms off to go clean her dildo, the only mundane thing coming to her mind to cool off.

Seungmin looks after her, his gaze trained on nothingness when she’s gone. Only when his legs feel numb and his heart calms to a normal beat does he stand up, grabbing the towel and turning to the kitchen. Hyunjin seemed willing to talk after all, so the most he can do is set up a calming tea for her and put some clothes on, like she told him.

With the water boiling and a cup ready to be filled Seungmin then goes to his room, grabbing himself some panties and joggers, a random sweater to throw on and he even brushes his hair, no matter what will happen he does not want to deal with the mess that would happen there if he left it unattended.

It apparently takes longer than he expected, because when he comes back to the kitchen Hyunjin is there, dumping the teabag in the trash and sitting down at their small table to look at the newly arrived expectantly. Seungmin helps himself to a glass of water before sitting down. This is going to be interesting.

“Let me get my facts straight: First you have a dick, now you have a vagina and you tell me you’re a succubus. From what I see there are a few possibilities of what is going on.”, Hyunjin places the cup down in front of her and Seungmin notices the way her fingers shake around it. “Either I am having a crazily realistic dream, you’re pulling a very intricate prank on me, or I’m going crazy and am already so high on drugs that I don’t know what reality is anymore.”

Seungmin wishes he could smile at it, any other time he would, because despite being confused Hyunjin speaks like it’s completely rational, like she isn’t going over the words over and over and over in her head. But Seungmin knows her well enough to realize that’s exactly what she’s doing.

“Have you considered that the easiest answer might be the right one?” Seungmin doesn’t mean to sound a cryptic as he does, and he cringes after the sentence leaves his lips. Hyunjin finally, _finally_ smiles, chuckling in that beautiful way of hers that lights up Seungmin’s whole world.

“So the dream one?” She asks, seeming a tiny bit relieved but in the way her eyes keep flickering from one point on Seungmin’s face to the other, the demon knows she doesn’t quite convince herself.

“That this is all real and you’re just learning something new about the world and the people in it.” _People_ might be a far stretch but Seungmin has never had this talk, never even thought about it because it is so incredibly taboo, he might even be killed for it.

“You mean to tell me that there are demons and angels just living alongside us humans and we never noticed? Doesn’t make much sense to me...” Hyunjin leans back, trying to fake certainty and also to steady herself on the back of the chair. She might not know much at all about the world she called boring not even an hour earlier.

“Well, I never met an _angel_ , so I wouldn’t be sure about that one.”, Seungmin ponders, quickly dodging a tea towel thrown his way. Hyunjin is staring him down now, ethereal and dangerous and maybe Seungmin _has_ seen an angel before. “Then again, humans _did_ notice. Do every day. I mean how else would you know what a succubus is. There is always a grain of truth in the stories you are told.”

“You sound like a stupid teen novel, Minnie.”, Hyunjin chuckles again and Seungmin’s heart picks up because she used _his nickname_. How bad can it be if she is already back to using his nickname. “I just don’t... understand. Or believe to be honest. Like how can that be? You just switch between female and male anatomy with a snap of your fingers? And you live off of... sperm? It just sounds so utterly _stupid_.”

“Wow, offensive. Calling my whole existence stupid just like that.”, Hyunjin sends Seungmin another glare, enough to tell him to cut the bullshit and answer her questions. With a sigh the demon continues. “It’s not _that_ easy. I don’t just snap my fingers and then there’s a penis, it’s more of an _organic_ thing. A morphing from skin to another form. Doesn’t even have to be a penis, I shape to whatever the other person needs.”

“You _what_? Like _anything_?” Hyunjin is on the edge of her seat again, staring at Seungmin like he is from another planet, he might as well be for everything she knows.

“Pretty much, it can be as simple as size or form or colour, or it can be something else entirely. I’ve heard of some creating tentacles and knots, completely loose vaginas or virgin ones. A lot is possible.” Even Seungmin blushes because he never talked that _explicitly_ with Hyunjin, never used so many sexual words in front of her and a part of him is still scared that she will scream at him or run away entirely.

Hyunjin on the other hand stops thinking after the word _knot_ , because Seungmin just said that her deepest darkest desire could turn reality more than from just a bad dragon dildo. She could actually experience it for real. Her mind lags for a few seconds and she only snaps back when Seungmin coughs lightly to get her attention. His face is that of amusement.

“You good?” He asks, his voice so soft it actually goes straight to Hyunjin’s nerves and calms her down enough to nod and take a sip of her tea. She didn’t even notice how cold her hands turned until she touches the hot cup.

“Y-yeah, just a lot to take in.”, she takes another sip, not caring about the liquid burning its way down her throat. “Okay so your down-area is a shapeshifter, got it. But what for? And how did it happen? Is it like a vampire thing and you needed to get your dick bitten off and then got something implanted there, _oh god_ , that sounds traumatic, are you okay?”

She is babbling, running to conclusions and it’s so unapologetically Hyunjin, Seungmin feels deep in his non-existent soul that she’ll be fine, that she won’t lose her mind over this. A breath he didn’t know he was holding finally leaves his lungs as he sits forward to mirror his friend and takes a sip of his drink. The water is lukewarm.

“It’s definitely not a vampire thing. I was born like this.”, the words hang heavy in the air for a second and Seungmin swears he can hear Hyunjin swallow down a knot in her throat. “Or I guess I was _reborn_ like this. I’m a... demon. And demons change and evolve just like humans, so I decided to choose this path.”

“ _Demons_!”, it’s a screech. “You have a lot of explaining to do for that one in general but first off, _why_? Why a succubus?” Hyunjin can’t say she’s an expert in what kind of demons there are, but she would bet that there are better ways to spend their lives than trapped amongst humans. She’ll be sure to ask about it all later on, when her mind is done processing _this_.

“A life full of sex and lust sounded pretty great to me back then. And I wanted to see new things, experience a new species, so the decision was easy.” Seungmin sometimes wishes he would’ve decided differently, would’ve chosen a different path for himself, but when he looks at Hyunjin and sees that curious, self destructive sparkle in her eyes he quickly forgets about that. Nothing in the universe could make him want to go back.

“So you live for sex? You must be pretty bad then, I don’t see a lot of people visiting you for it after all...” It’s a challenge for sure, Hyunjin’s smile says as much, but Seungmin isn’t even offended by the implication, just very happy that she seems to get more and more comfortable with the situation.

“I don’t live _for_ sex, I live _off_ of sex. If anything, humans live for it.”, Seungmin has the urge to poke his tongue out, deciding against it because after everything that happened _that_ would probably be the weirdest thing. “And where do you think I go every Thursday evening? Game night, really? You know I’m not good enough at games for that one...”

Another tea towel is thrown his way, Hyunjin has the unfair advantage of sitting directly next to the cupboard where they store them. The challenging smile is gone again and replaced by an annoyed huff and pout.

“I only found out about you _today_ , don’t act like I should’ve noticed sooner.”, She actually sticks her tongue out at Seungmin, making him gasp dramatically. Yes, they are going to be fine. “So how does it work? You have to... _eat_ someone’s sperm?” Either the wording or the pure thought makes Hyunjin shiver, Seungmin quickly following after.

“ _Yikes_ , that sounds revolting, but I guess so? We don’t have to _eat_ it to get energy, we just need to be the reason for someone to reach an orgasm. And already having sex without an orgasm helps us out a lot. It’s an energy thing, pretty hard of a concept for humans to understand because you don’t really have receptors for it.” Seungmin pushes a strand of hair behind his ear sheepishly.

Of course, there would be more for Hyunjin to not understand. Whole energy levels humans can’t detect? Sure, she was aware that there must be so many things humans just aren’t capable of, animals communicating over incomprehensible channels being more than enough proof of that, but something even bigger? Sexual energy as a true _source_ for other beings to feed off? Mind-blowing would be an understatement.

“Okay, so a demon with a shapeshifting sexual organ feeds off of horniness. Did I get it right?” Hyunjin massages her temples because her head feels like its about to explode. Maybe finishing her tea will help.

“The gist of it... but that’s more than enough for one day.” Trying to smile apologetically Seungmin takes another sip of his water, just to help cover the awkward silence between them.

“You don’t even know, Minnie… I’ll go take a shower.” Because a hot bubble bath just doesn’t feel right when you just learned that your whole world is so much _more_ than you could’ve ever expected. The last sip of tea doesn’t help against the headache.

✨

Seungmin busies himself with cleaning the kitchen and living room while Hyunjin is in the shower, now sitting on the sofa and mindlessly scrolling through Netflix to find _something_ to distract himself. Even as a demon, this situation feels horrendous, he doesn’t even want to begin to know how it would feel to be in Hyunjin’s shoes.

After a few restless minutes of scanning through the newly added shows, Seungmin’s roommate finally comes out of the bathroom a flowery scented waft of steam gushing out after her when she enters the living room.

Her attire is comfortable, ready for an evening in, not that Seungmin expected it any other way. After the day’s events he will stay in too. He should feed soon, but it doesn’t have to be this evening, Friday or even Saturday should be fine too.

The demon looks up from the TV when Hyunjin stands next to him, not sitting down as if she’s waiting for something. She looks gorgeous like this, towering over Seungmin, all long legs and only an oversized sweater and shorts hiding the rest of her body. Seungmin never really looked at her as someone he could feast of, but suddenly it is ruining his every thought, so much want surging through his blood he feels like a freshly turned succubus again, roaming the earth for the first time in search of a victim.

Just that these days he doesn’t want a _victim_ anymore, wants someone who is infatuated with him not only because of his demonic powers luring people in, but because of _him._ As a person. He doubts Hyunjin would think that way of him and swallows down the sour taste in his throat.

It will surprise him in only a short while oh how wrong he can be, because Hyunjin is biting her lips still thinking about _the possibilities_ more than the situation of a literal demon being her roommate. Seungmin never made a move to hurt her in the year of them living together, so why would he do so now all of a sudden?

“I still don’t quite buy it.” She finally says, fiddling with the sleeves of her sweater that cover half of her hands and Seungmin is ruined because he desires his best friend, needs her to pull him together again because his whole body is _screaming_ at him to use his powers to lure her in. The demon thinks it must be Hyunjin who is the succubus, never ever did he feel so out of control before.

“I-" He begins, glad that Hyunjin interrupts him because he would’ve stumbled embarrassingly over anything he would’ve tried to say. Seungmin feels like he might start to drool if Hyunjin keeps standing there biting her lips as if it’s nothing, when for Seungmin it is _everything_.

“Show me.”

And were before spit was collecting at the sight of his friend, Seungmin now feels his mouth dry out, because Hyunjin wants proof that he is a succubus, wants to see him change. It is a nightmare, a horribly beautiful, painfully delicious one, because Seungmin has never shown himself like that before. Never bared himself up and shown how his supernatural body switching between shapes.

“Minnie, _please_ , show me. I just want to understand. You know me, I want to know and understand everything I see.” And Hyunjin sounds absolutely desperate, helpless and vulnerable because it hurts to have been left out of a such a big thing for so long.

Seungmin can basically taste her yearning for knowledge on the tip of his tongue, heavy and consuming and he truly knows her, knows that she will ruin herself in the quest to learn everything she can, even the dangerous things she should never have known about in the first place. How can he deny someone with such pure intentions to just _know_?

“You know that I’ll have to show you my-"

“I know, Seungmin, I’m not delusional.” Hyunjin is more than impatient at this point, the shower having been more torture than relieve because all she could think about was what else there is. What else she misses every day in their vast world. What Seungmin does to get the energy he needs from other people. That last one in particular made the shower a way bigger hassle than it needed to be.

“Okay then.”, Seungmin stands up to be able to pull his pants down, now suddenly so close to Hyunjin he can feel the heat radiating from her body, the scent of her shampoo filling his nostrils and with them every single cell in his body. “I’ll just...”

He plucks his thumbs under the waistband of his pants to show his intentions, pulling them forward and he catches a quick flash of red and curses himself, wishing he wouldn’t have put on panties earlier because this whole situation is already strange enough, he doesn’t need to make it even weirder with his clothing choices.

With a sudden movement Hyunjin startles Seungmin as she sits down on the couch, leaning back like someone would for a lap dance, which is not at all what is happening between them right now. As much as Seungmin would like that.

“I can see better from here.” Hyunjin mumbles and pulls a pillow to her chest to hug it tight. For support. Seungmin has to fight a bear inside of him to not bend forward and snatch Hyunjin’s chin between his fingers and ask her to repeat herself. This isn’t even his succubus side speaking, he is just beyond horny for his roommate, but he can’t let it consume him.

With shaking hands, he finally slides the pants down to his knees, revealing red lace hugging his hips. Seungmin isn’t sure if Hyunjin really gasps or if it is his imagination playing pranks on him. With another deep breath he pulls down the small stretch of fabric too, revealing soft skin and peach fluff because he likes _soft_ , not stubbly or hairy, just soft. And if Seungmin has the power to change it to that, why not use it?

“So, this is your... default setting?” Hyunjin asks and her eyes are fixed on Seungmin’s middle, roaming him and it burns, his whole body burns up with embarrassment because he is wholly and truly being examined by his best friend.

“N-no, the default is a penis. I just like this more.” The last words are whispered so quietly, Seungmin is surprised Hyunjin even picks it up. She definitely does however, because for the first time since losing his pants, Seungmin’s best friend is looking up at him, directly into his eyes and it makes him blush even more, he wishes he could melt into a puddle because this is just _too much_.

What powers must Hyunjin possess to fluster a true demon so deeply? Seungmin doesn’t dare to think about it, because maybe angels are real. And maybe he isn’t ready to face one.

“That’s actually really cute.”, Hyunjin sounds like she means it, nearly cooing at Seungmin if she wouldn’t be so nervous to see what comes next. “Now change it, come on, _come on_.”

“Eager much?” And when Hyunjin looks up at Seungmin this time she finally blushes too, red sprinkling her face in the most pretty way.

“I don’t know how, but I will kill you.” It’s a cheap threat, on one hand because she physically could never kill Seungmin, on the other because she would never dare to even _think_ of that, just wanting things to hurry up because her curious brain is eating at every nerve in her body.

With a chuckle Seungmin complies, spreading his legs a bit for a better stance as he concentrates every single one of his thoughts on his body. It might be the most natural thing to change for someone else, but just for himself it always takes a bit of mind work and the added pressure of a human staring so openly at his private parts isn’t helping either.

Hyunjin can’t really believe her eyes, one second Seungmin’s _vagina_ looks perfectly normal but in the next second the skin is starting to ripple like water disturbed by a stone. It begins to move and morph, plush lips suddenly being sucked in and closing up, only for the very front of Seungmin’s pelvic area to bulge out and slowly, steadily grow into the vague shape of something phallic. It’s like watching clay be formed in a time lapse, more and more details appearing slowly. Veins and folds, foreskin, a slit and for a second Hyunjin wonders if it hurts to form a new urethra every time but she stores the question away to the other dozen she found this day. For a later time.

With a final bounce the transformation completes with balls dropping between Seungmin’s legs and he sighs a breathe of air in relieve, as if he just had a presentation and got through it without stumbling over words or forgetting a sentence. Weirdly enough, Hyunjin feels the exact same way, her throat uncomfortably dry, because Seungmin is _naked_. And not only that, he looks so handsome, pretty in the way his face is flushed pink and he gnaws on his lip nervously.

Hyunjin is sitting there with her mouth hanging open and it’s so obscene how close she is to Seungmin, it would be suggestive at any other time. The demon has to actively stop his thoughts from running into _that_ direction, not needing a boner to make this even harder. Pun intended.

“That’s a penis.” Hyunjin says with such finality it makes Seungmin giggle. The soft sound is so familiar, has been directed at her so many times and even in their questionable position it has its usual effect, a big smile soon lighting up Hyunjin’s face.

“Very observant, Sherlock.” The demon teases voice quivering from smiling so widely. Hyunjin’s face falters then, the smile leaving her features for a painful second before being replaced by an even brighter one, the sweetest laughter coming from her. It’s so high, so unlike her usual voice and Seungmin doesn’t get to hear it very often, knows that Hyunjin is embarrassed by it, so it means even more when it is directed at him and him only.

Their eyes lock and from the pure absurdity of the day Seungmin can’t help but chime in, their voices mixing, and it snowballs into a full-on laughing fit, neither of them being able to stop until tears are pricking at Hyunjin’s eyes and Seungmin’s chest is hurting. It takes even more time until they catch their breath, their eyes never leaving the other until a playful smirk appears on Hyunjin’s face and she looks down again. Seungmin nearly forgot he is still naked waist down and he pulls on the hem of his top, trying to cover up but failing.

“It’s not very big...”, Hyunjin says then, cockiness evident in her voice and with no need for it, the words hurt Seungmin’s ego. “I thought you would be whatever a person needs…” Why does she have to look up now, when Seungmin is blushing furiously again?

“I’m not even hard, of course it’s not big. And despite that, I can only turn into whatever monster cock you want if we were to really get it on.” Seungmin bites his tongue, because this must sound so utterly _wrong_ coming from him, but he can’t deny that he actually wants to find out what it would be that Hyunjin desires.

“Then let’s do that.”

The words are pure paradise, Seungmin feels like this must have been what made Eve eat the forbidden fruit, and maybe Hyunjin isn’t an angel after all. Maybe she is Satan herself.

To confuse the demon even further she stands up and now they are so _close_ , it takes Seungmin’s breath away. Even just the few centimetres of height difference between them are enough for Hyunjin to look down at him in such a _dark_ way, it is terrifying and inviting and just too much.

“You… _what_?” Seungmin asks unceremoniously, trying his hardest to stay _this_ version of himself despite his own body screaming at him to awaken his succubus side, to lure Hyunjin in and finally try what must be the most endearing taste in the world.

Because he has to let go and free his demonic side, a thing that immediately coats him in layers of lustful dark magic to be as endearing to humans as possible. It heightens his senses in a way that he will be able to smell Hyunjin’s emotions in her scent, that he will be able to taste her desire in such a fulfilling way, enough to push his energy levels up already.

He would be able to look and feel so inviting, no mortal would be able to say no. But Seungmin doesn’t want that. He wants Hyunjin to ask for this on her own accord with no enchanting flavour of seduction to cloud her mind. It is as if he is fighting a war with himself, these two sides of Seungmin battling in his chest and he can’t let that demonic side win, won’t let it, despite his body shaking and begging him to just give in.

“Let’s _get it on_.” Hyunjin tries her hardest to stay resilient, to sound challenging when she repeats Seungmin’s earlier words. She definitely doesn’t feel that way, her heart beating harder than ever before and her core clenching in a want she didn’t feel in a long time.

She wants Seungmin, has thought about it a few times before because he is enticing to say the least, soft and not as intimidating as men so often want to be, so of course fantasies have crossed her mind. But this Seungmin, truly demonic and speaking about sex in such a normal way because he lives off of it, the prospects of what that could mean. Hyunjin needs him.

The spell of toughness is broken with her next words that come out whimpered and desperate, finally showing her true side of need and want for her best friend that conveniently is also a succubus able to satisfy her deepest and darkest desires. How could she possibly say no to that?

So, with a last deep breath Hyunjin throws her last nagging thoughts out of the window and breaks eye contact for a moment, only to flutter her lashes in a way she knows is alluring. She might be laying it on thick when she slowly licks her lips, but the way Seungmin’s eyes darken by the second is enough proof that she isn’t doing it for naught.

“I-if you want that…” The tremble in her voice is accidental, Hyunjin’s nerves slowly but surely getting the better of her and she thinks Seungmin doesn’t want to, when his reply takes a second too long.

“Jinnie, this isn’t going to be like your usual boring fucks, there’s a power behind it you can’t even _realize_.” It sounds like an insult in every way. That Seungmin knows Hyunjin’s sex life has been less than exciting for months, that he presses on the fact a whole different species was hidden right in front of her.

It’s a good thing that Hyunjin doesn’t mind getting insulted.

Hell, if anything she gets off on it, visible in the way her knees buckle and Seungmin has to reach out and steady her. Even the touch over a thick layer of fabric feels like more they have ever done before and Seungmin really needs to get her consent now or he will snap.

“Then show me, Seungmin.”, Hyunjin doesn’t get through the name without her voice breaking and suddenly she feels a heat boil in her throat, different from the inherent need in her bones. Pure frustration slowly coming to the surface. Her hands fly to Seungmin’s shirt to fist into the fabric, right above his heart. “Fucking show me your all, _please_.”

The thing is, Hyunjin easily submits to her partners, begging even in the early stages of whatever sexual adventure she finds herself in. But begging before it even _got_ sexual? That is pathetic, even for someone like her and she can’t bear to look at Seungmin, her best friend who is probably disgusted at her.

The sound or remark she expects doesn’t come, instead a low chuckle echoes through the silence, deep and raspy and a tone Hyunjin has never heard from Seungmin before. She can’t help but look up, immediately regretting it because the look on the demon’s face sends a shudder through her, so dangerous goosebumps arise all over her skin.

It is a smirk that truly only can be described as demonic, underlined by the way Seungmin wets his lips with his tongue only to come to a rest upon one of his canines, making it look sharp enough to pierce through skin. Hyunjin can feel her lips begin to tremble, somehow her body switching into fight or flight mode at the picture in front of her. She doesn’t dare to look up any higher than Seungmin’s mouth.

“Oh Jinnie,”, Seungmin lures, his voice like honey but somehow rippled with shards of glass, pricking at Hyunjin’s mind and making her mouth fall open with heavy breathes. “Look me in the eyes and seal the pact.”

They haven’t even gotten as far as discuss any of the formalities coming with being a demon and with a clear mind Hyunjin would definitely add ‘ _What does a pact with a demon entice?_ ’ to her ever-growing catalogue of questions. In her current state of trembling and panting and _needing_ however, all she can do is follow each and every demand Seungmin lays out in front of her.

So Hyunjin does as she’s told and looks up, quivering eyes travelling over pink blushed caramel skin until they meet Seungmin’s eyes. Eyes that she thought she had known before but now look so different and otherworldly, unlike anything she has ever seen before.

Seungmin’s irises have transformed to a deep dark pool of black ink, swirling and somehow pulling Hyunjin in and she can feel herself actually fall for a second, everything blacking out around her until she can feel her feet again and the lights in their living room nearly blind her.

It all changes then, beginning with the whites of Seungmin’s eyes slowly making way, splotchy dark filling them up like ink dissolved in water until they are completely dark, now unwavering and shiny but so _alien_ and frightening Hyunjin feels as scream of horror build in her throat.

It doesn’t come, because something erupts around Seungmin, a mist of purple slowly spreading through the air like smoke, small lightnings of electricity lighting it up like a tiny and beautiful thunderstorm. The waves of it slowly wrap around Hyunjin until they engulf her completely and with it any trace of fear leaves her body.

She closes her eyes then, because it feels so warm and so _familiar_ , Seungmin’s scent filling her as if she is laying right in the crook of his neck. It is comfortable and safe, fresh yet soothing and it feels like everything she has been missing all her life.

When Hyunjin finally dares to open her eyes, scared to wake up from this dreamy cloud of _Seungmin_ , all traces of demonic darkness are gone, his eyes are back to normal except that his pupils are dilated from lust. The cotton feeling around her stays too, just tuning down from completely overwhelming to a constant thrum on her skin, as if the sparks of purple are still licking over her, just invisible to her eyes. Maybe that’s exactly the case and her view of Seungmin’s powers was something of complete taboo to humans, something they should not be able to lay their eyes upon.

Seungmin still has his hands on her arms from holding Hyunjin up earlier and she is glad for it, worrying that this might be a dream and as soon as his touch leaves her body the demon will disappear into nothingness like the purple mist.

His grip has tightened however, and he is panting now too, lips parted and eyes roaming all over Hyunjin too unfocused to fix on a certain point. The feeling is similar for Seungmin too, sealing the pact making way for all of his powers to roam free and he can see right through Hyunjin’s little gasps and huffs. Can taste her desire on his tongue and he can feel each and everyone of her secrets in his gut, knows instinctively what to form to, what she would like if they were compeletely naked now.

Hyunjin has always been beautiful, painfully so, for both her and the people around her. She is one of those persons that gets stared at in the bus, asked to model by random store managers, that gets hit on every time she leaves the house. She has everything others could want: long legs, the perfect proportions of hips, waist and shoulders, long black hair with the most natural volume and shine, she could make snow-white jealous. Full lips and a smile to die for, with eyes so bright and fox like, she could trick anyone to fall for her.

Now, with her true taste on Seungmin’s tongue and her essence running through his every nerve she is the most terrifyingly beautiful power there is, the demon doubts he will ever be able to go back to other humans, not when he knows what heaven tastes like.

“Bedroom.” Seungmin utters, wishing he could gain some of the confidence back he felt earlier but right now he just wants Hyunjin in a bed, preferably naked.

So, he takes a step back, careful to not tumble over his pants around his ankles as he rids himself of them completely. He then makes for Hyunjin’s bedroom, wanting to make this a special experience and not have it done in his room that he fucked so many random people in. Because Hyunjin is anything but _random_ to him, the most important human he ever got to feed on to be completely real.

She stumbles after him, trying to keep up but tripping over her own feet because they feel close to numb and she is way more concentrated on Seungmin’s tight grip digging into her lower arm. With a chuckle the demon turns around, Hyunjin crushing into him in surprise and with a power she didn’t know Seungmin possessed he picks her up, bridal style, to carry her to her room.

“You’re so cute!” He coos when they make it through her doorway, the way Hyunjin is clutching at his neck like her life depends on it is so utterly adorable, Seungmin can’t hold the words back.

“I’m not! I’m ho-“ With a yelp Hyunjin gets thrown on the bed, landing softly in the pillows with Seungmin standing in front of the mattress looking at her like something to eat. Which, to be precise, isn’t all that wrong given their situation.

Hyunjin loves it. Loves the way it makes her feel so helpless because Seungmin is a demon, what could she even try and do against him. Of course, she doesn’t want this to stop anytime soon, wondering what Seungmin will have up his sleeve and if he will finally be the one to stop her dry streak with lame men.

She has a suspicion that he will definitely do just that, when he basically rips his shirt from his body, eager to get rid of the last bit of hindering fabric. Seungmin basically pounces on Hyunjin then, pulling her up by the front of her sweater and together they somehow get it off in a mess of limbs and fabric.

She isn’t wearing anything underneath and with dread Hyunjin realizes this is the first time Seungmin sees her topless, immediately going to cover up with her hands crossing over her chest. The demon just _tsk_ ’s at her and back is that devilish grin that Hyunjin has quickly come to hate and love all the same, a thrill of panic surging through her veins that makes her feel even hotter than before, throbbing and wet and she can feel it sticking to her all over. Sweat beading on her skin, eyes becoming more and more shiny and her shorts are already damp, sticking to her in a more than uncomfortable way.

“Don’t be shy now, baby.”, Seungmin says with that voice designed to lure in prey. Hyunjin can’t hold back a whine at the nickname. “I want to see all of my pretty Jinnie.” 

A whine turns to a needy moan and she lets herself fall back into the softness of her bed, back arching up because even these words feel like so much _more_. More pleasure that she or anyone else could give her, more sweetness coating her mind to nothingness, more emotions running through her, because this is still Seungmin, her best friend, and they are about to fuck. Hell, if she’s lucky she will get the sex of her life and that will definitely change their relationship forever.

At a low growl, a most guttural sound Hyunjin has never heard from a human, she looks up from where she has her face pressed into the pillow. Seungmin looks like he is mad, arms crossed over his chest and his eyes scream danger, but Hyunjin can’t remember what she could’ve done to make him this angry.

“Already so gone you can’t follow basic orders?”, Seungmin’s voice reverberates through Hyunjin’s whole being, something in their _pact_ making him feel like a part of her, his voice a savior in the need for touches and a killer in the meaning of his words. “Pathetic little thing, let me help you.”

And with that Seungmin is straddling Hyunjin, not caring about his cock being squished uncomfortably between them because he will change soon anyway, accommodate to whatever Hyunjin would want.

He rips Hyunjin’s arms apart with ease, pinning them above her head with inhuman strength. He only needs one hand to keep her writs pushed down, could even hold up against her struggling and trying to free herself, which she doesn’t try to do in the slightest. The opposite even, keening against Seungmin and pushing up against him as his free hand slowly travels down over her cheek.

As if on instinct, Hyunjin’s mouth opens with a moan, tongue lulling out to lap over Seungmin’s fingers. The demon always suspected Hyunjin to have something of an oral fixation, always chewing on gum or her lips, nibbling on her nails and the sleeves of jumpers, effectively ruining the hems. This just proves his theory, because she opens up even wider, inviting him in and how can Seungmin say no to such full lips baring entrance for him?

He slips two fingers into the wetness, groaning at the way Hyunjin immediately closes her lips around them and sucks lightly, tongue travelling around them like she knows what she’s doing. She probably does, always having had more than enough possibilities to use her mouth on whoever she desired. Beauty can surely be a blessing.

For Seungmin it feels more like a curse, because right now he is bonded with Hyunjin, tighter than anyone before and tighter than anyone ever will. She’s his to take and ruin and she is using skills on him that she acquired on _other_ people and none of them deserved her.

With a growl Seungmin bends down then, his hand leaving the grip around Hyunjin’s wrists to steady himself on the mattress as he mouths along her neck, nosing and breathing everything in he can get. His head has become a mess of _mine, mine, mine_ and despite being the succubus between them, he is as much under a spell as Hyunjin, especially when she sucks his fingers in completely, moaning around them and licking like her life depends on it.

Seungmin can’t hold back anymore at that, biting down where his face is nuzzled in the crook of Hyunjin’s neck and he lives in the way her mouths goes slack around his digits, drool running out of the corner of her lips because she keeps swirling her tongue around, trying to keep some of the stimulation up.

There is no mercy in the way Seungmin bites and sucks, hard and it brings blood to the surface easily, marks of deep red being left all over Hyunjin’s neck and collar bones and Seungmin doesn’t stop until he can barely see a stretch of unmarked skin. He kisses over the marks tenderly then, making his way over to Hyunjin’s ear.

Her scent has become nearly unbearable, not only her usual one, because like this, Seungmin can smell _everything_. He can smell every drop of sweat, every wave of pleasure hitting Hyunjin and he can smell that she is soaked where her thighs are pressed together under Seungmin’s hips, probably so close but never quite getting enough from the demon, needing more.

When Seungmin finally arrives at her ear he can’t help the chuckle from leaving his lips, because Hyunjin is properly ruined already, all from him and it isn’t all his demonic doing. That possessiveness is _his_ only, unnatural to demons who take any and every human, no regard how many they had before. With Hyunjin, Seungmin cares deeply. Needs to make sure she will never enjoy anyone else again.

“You’re mine, Jinnie.”, He growls in her ear then, pressing his body against Hyunjin to hold her together as she writhes and moans underneath him. “You’re bound to me through a pact and when I’m done with you, you won’t remember anyone who came before. You’ll be mine inside and out, ruined for everyone else. Isn’t that right, princess?”

Seungmin retracts at once, pulling his fingers out of Hyunjin’s mouth with a wet pop and sitting back on his knees to look at his work. The human’s neck is completely covered in bruises, red and purple and some in the shape of Seungmin’s teeth because he really didn’t hold back, didn’t care to do so because he could literally taste that Hyunjin loved it. That she lived for the pain in that moment.

A string of curses leaves Hyunjin’s mouth along with whiny moans and she can barely bring up enough strength to wipe her lips before speaking. When she does, it is trembly and low, barely audible if it wouldn’t be for Seungmin’s heightened senses.

“ _Please, Minnie._ ”, she whines, blinking up at him through wet lashes. “Please fuck me, I need you so bad.” She is nearly sobbing, feels so done already and so _empty_ , she needs something to take the edge off of her yearning quickly, or she might combust.

“So eager, my princess. But I don’t think that’s what you _really_ want right now.” Seungmin’s voice is devilish and dark. He knows what Hyunjin wants, his body already has a plethora of weapons against her because he has seen each and every one of her secret desires. Knows that what she wants most right now is not a cock filling her up. That is for later.

Seungmin stands up, pulling Hyunjin to the edge of her bed by her ankles with a strength that has her feel so weak in the knees, she is glad she’s already laying down. He doesn’t stop there, soft fingers travelling up over smooth skin until he reaches the hem of Hyunjin’s shorts. The demon comes to a halt there, bending down to kiss and nip at Hyunjin’s hipbones, lightly lap along the edge of the fabric until she is a withering mess underneath him yet again.

“S-stop teasing and get them off, Minnie.” Hyunjin huffs, pressing her hips up to get him to move quicker, to finally get closer to having something inside her, because despite of Seungmin’s words she only feels that emptiness inside of her, needs to be filled.

“But you’re so cute when you’re desperate.” Torturously slow Seungmin continues to kiss and bite and suck his way to Hyunjin’s other hip bone, loving the way he can feel her skin erupt in goosebumps under his tongue.

“You know I-I’ll be even more desperate with you in-inside of me.” Small moans prohibit her from continuing the sentence without stumbling over words, but Seungmin is biting down at just the right moments, unapologetic and evil and Hyunjin might cry during sex for the first time in five years.

“Oh, I know you will be, princess.”, Seungmin looks up at his friend, trying to not smile at the way she glares at him through her lashes, nose scrunched like she’s actually mad when both of them know she is far from that. “Maybe I will give you what you want if you beg like a good girl.”

It is truly cruel how Seungmin can play Hyunjin like it’s nothing, act out her desires so easily, because he knows them all. He can’t only feel all the things his body could change to because of her wishes, he can also clearly see all of her preferences and kinks, every pet name that makes her feel good and every other thing that could pleasure her. And one of them just seems to be to make her beg, to make her feel utterly humiliated and baby her down to nothing more than a cock-hungry pillow princess.

“ _Fuck_ , Seungmin, you don’t know how hot you are.” Hyunjin whispers, quickly changing her mind when he stands back up and laughs at her in the most condescending way. Seungmin is probably well aware of just _how_ hot he is.

“I didn’t ask you to flatter me, princess, you’re supposed to beg.” He basically spits the words in a way that they sting, despite the use of such a precious pet name in between and it is enough to take Hyunjin back to a state of mushy horniness, brain shutting down again by the sheer power of Seungmin’s voice.

“Please, Minnie, _please_. I need you so much, need you inside of me, _please_.” Hyunjin bites back the pet name playing on repeat in her head, not ready to embarrass herself that much in front of her best friend.

She doesn’t realize that he knows it of course, and Seungmin doesn’t let her know either, not yet anyway. He will be sure to make good use of the knowledge later on, somehow intrigued how it will feel to be called _that_ during sex. He’s used to a lot, but some things are even new to him and Hyunjin seems to have a whole artillery of those to try out.

Finally, Seungmin’s fingers curl into the fabric of Hyunjin’s shorts and she is eager to rile her hips up to make it easier for the other to get them off. The shorts stick to her, wetness soaking through them and darkening the fabric and it should be embarrassing when Seungmin runs a finger over the spot before undressing her, but it isn’t. Instead it is too much for the touch-starved girl underneath him.

When they are off, she opens her legs wide, hoping that Seungmin will just plunge in and obey her wishes. She should know better by now, that her demon is in no way rushing this and taking his sweet time every step of the way. It hurts when Hyunjin realizes this once more, a punch to her gut that she will have to wait even longer.

Seungmin looks at her dead on, with those dark abysses that make Hyunjin feel stripped off more than just clothes and it is so intense, she can’t break away from it, no matter how badly she wants to. The demon keeps her gaze locked on him when he brings the fabric of her shorts to his face, nuzzling into the wetness and he doesn’t just breathe into it, no, he all but inhales Hyunjin’s scent, seemingly the only thing keeping him grounded to this world.

Hyunjin doesn’t know what she expected, maybe that Seungmin would stay unaffected like a robot and just pleasure her for the night and then return to his normal self. She doesn’t know, but something in the way his eyes roll back into his head and how he pushes the fabric impossibly deeper into his face, chasing after every bit of Hyunjin’s sweetness, as if her spoiled shorts are ambrosia to the demon, something in that makes her realize that this is still her normal Seungmin. And that he is in no way an automaton chasing after Hyunjin’s release, he’s in this just as deep as her.

It takes even more time for her to notice that something else doesn’t stay unaffected and with dread Hyunjin notices that she must have missed it, only the last ripples like water on Seungmin’s skin a reminder that he just changed to something of Hyunjin’s desire.

Only when he slowly lets his hand travel down his torso, does Seungmin drop the shorts, his eyes fixed on Hyunjin as always. He dips a finger between his folds, pressing ever so slightly down on his clit only to bite back a moan, because he loves this feeling. Love how it pulls higher and up into his core, lighting him up all over. He dips further then, pressing in deeper between his swollen labia to feel just how affected he already is from Hyunjin being so utterly herself on the bane of his hands.

“I’m so wet already, Jinnie. All from you and you aren’t even doing anything, just laying there and taking whatever I give you.”, Seungmin lightly pushes a finger into himself, only to gather some of the liquid and take it to his mouth to have a taste. As always it tastes like nothing to him. “What do you want me to do, princess? Because this is apparently more important to you than getting filled?”

Hyunjin was convinced that all she needs, all she yearns for in this moment is to be fucked wholly and truly, but now, with Seungmin sucking on his own juices and looking so pretty in the way he blushes from it, she knows that she wants something else. Something she never tried before but will finally be able to fulfill.

“Want to… want to eat you out, Minnie…” She mumbles and even though Seungmin knows like he knows all of her, it feels breathtaking to hear it out loud. This time he also doesn’t have to hold himself back from making Hyunjin repeat herself, so he quickly bends forward to snatch her chin between a spit-slick index finger and his thumb.

“What did you say, little one? I didn’t quite catch that…” And Seungmin tilts his head in this way that Hyunjin thought was cute until now. It is anything but that, degrading at best. So all she can fathom is to do what she’s told.

“I want to eat you out. Please let me, _Seungminnie_.” She whines the name in hopes to convince the other that she is worth it, that she deserves to do what she wants, because she feels so starved for it. Like all she was ever missing from her life is right in front of her between Seungmin’s legs.

All-granting, Seungmin smiles then, pulling back only to kneel on the bed next to Hyunjin. “Of course, baby. Whatever you want.” He says, acting like he would give her everything if she just asks, manipulating in a sense that makes Hyunjin’s head spin with a sudden want she never felt so strongly before. To be made completely Seungmin’s to a point where she doesn’t even remember her own name.

The human doesn’t have a second to think more of it, because Seungmin is next to her head now, spreading one leg above and over and yes, he’s definitely straddling her head now, the object of her desire right above Hyunjin’s face. She doesn’t even care that he is kneeling on her hair, pulling on it accidentally, because maybe she likes that sting too.

“Your eyes are so big, like you’re a kid in a toy store. So _precious_ , little Jinnie.” And with that Seungmin lowers himself down, until he’s barely even hovering above Hyunjin’s mouth, only waiting for her to open up and do what she desires.

Carefully, maybe even in a shy way, she does just that, poking her tongue out to catch a first taste of unexplored territory. Her eyes grow even wider then and like she knows what to do, her hands fly up to rest on Seungmin’s thighs, pulling him completely down until she is close to suffocating under him.

Hyunjin doesn’t know what she’s doing. At all. But she hopes that it is in some way pleasuring to Seungmin as she licks stripes over him, pushing his folds apart and lightly dipping into his wetness, so sweet on her tongue, so reminiscent of something that she can’t quite wrap her head around. It is definitely not how it should taste, not from a human at least, but Seungmin isn’t human. That’s why Hyunjin thinks he’s is allowed to taste like frosting and cinnamon and mint in a weird combination of nostalgic flavours.

At the first breach Seungmin nearly topples over, slapping his hands down to steady himself over Hyunjin’s fingers on his thighs, hoping that her strong grip will leave bruises on his skin. It feels good, even in that uncoordinated and inexperienced way and he can’t help but grind down against Hyunjin’s face ever so slightly, tongue digging deeper only to be pulled away completely and suddenly he can feel teeth, can feel Hyunjin suck on his clit and if she doesn’t stop soon Seungmin will be the first one to come that night. The demon can’t very well let that happen.

Blindly, Seungmin bends back and frees one hand to fumble his way down Hyunjin’s stomach behind himself. He arches even further until he can finally reach his desired spot, fingers running down between Hyunjin’s folds and she is _wet_ , soaking and dripping and her sheets will be ruined for sure.

At the sudden touch Hyunjin arches up to give Seungmin easier access, begging for him to just push a finger or two inside so that she can finally come and relieve some of that pressure that has been building for what seems like eternities. The demon chuckles through choked moans, because he wouldn’t dare to comply, wanting the first thing to go inside of Hyunjin to be his cock, a weird ode to his ego that it is _him_ stretching her open, not just his lame fingers.

At last, he does the next best thing, pressing down hard on Hyunjin’s bundle of nerves, making her moan out against him as he simultaneously presses his hips down and like that she comes for the first time, white spots clouding her eyes and the hit of it is enough to pull Seungmin right over the edge with her, coming undone on her lips that quiver against him so sweetly as Hyunjin comes down from her high.

The immediate effect a human orgasm has on the demon is similar to a drug, immediately energizing his body, blazing him up in want and hunger for more. With trembling legs Seungmin climbs down Hyunjin’s body, not caring about smearing a mixture of himself and saliva all over her chest.

It is only then that he notices that Hyunjin and him never even kissed before. The mess on her swollen lips reminder enough that Seungmin has sat on this pretty mouth but never so much as pecked the plush pair of lips. He can’t possibly stop himself then, pressing his lips against hers and effectively stealing away any breath of air she is trying to catch.

It tastes like nothing again. Nothing, mixed with _Hyunjin_ and her desperation as the kiss quickly turns from lips on lips to tongue and teeth, catching every bit of lust from the other’s taste. Seungmin knows that Hyunjin is just coming down from her first high but with it comes a wave of strong desire and where wetness is pooling between Seungmin’s legs, he can quickly feel his skin tingle and close up, forming and building and it feels different, bigger and way more sensitive than his usual cocks.

Out of pure curiosity he breaks the kiss, sitting up to look down where he is laying hard and heavy against Hyunjin’s soft stomach. He is bigger than _his_ dick, long and thick and Seungmin is sure that Hyunjin must have as big of a size kink as she has a pain kink, but who is he to judge. There is something else about him that Seungmin never saw before, like skin bunching at the base of his dick, waiting to be filled up. He knows what it is, Hyunjin’s sweet dreams enough to teach the demon all about knots and heats and slick, but _she_ doesn’t seem to realize, the pure thought of _dick_ enough to cloud her mind in hopes of finally feeling whole again.

Seungmin can taste it on the tip of his tongue, can feel that deep need run through his own bones because Hyunjin’s orgasm has given him more than his ten recent prey’s combined. A perfect match to his ever-hungry soul.

It might not even be this certain cock of his that is so sensitive, he then realizes. Maybe the connection he feels with Hyunjin, the pact they fulfilled by locking eyes, maybe it goes beyond normal bonds between a demon and a human. Maybe it isn’t the cold air hitting his erection that makes it throb in a steady, heavy pulse, maybe it is Hyunjin’s lust vibrating in her core, waiting patiently for Seungmin to ease her pain.

And if that is really the case, how could Seungmin possibly hold back from testing that theory out right now? How could he forbid himself double the pleasure if he could truly experience Hyunjin’s feelings as much as his own?

With that thought pushing everything else way to the back of Seungmin’s mind he settles down between Hyunjin’s legs, grabbing a pillow to prop underneath her to be able to go as deep as possible.

Seungmin is so lost in feeling, smelling, tasting, _being_ Hyunjin, he doesn’t even realize that she has become somewhat nonverbal, only light pants leaving her lips as she has her eyes locked on Seungmin. Her gaze is frantic, searching from one body part to the next with no clear aim in sight and as much as Seungmin wants to fulfill both of their desires, he doesn’t dare to go further without Hyunjin clearly showing him that she is _good_. He knows that she is, deep in his being, but the human in him needs some kind of consent, doesn’t dare to just take and not make sure it is fine.

He is between her legs, fingers trailing nonsense patterns on soft skin and Seungmin keeps repeating Hyunjin’s name, like a mantra, a prayer to get her back and him to calm down. It is basically impossible to completely retract his demonic presence at this point, not when the pact is intact and not close to being fulfilled, but Seungmin tries his best to pull it back. He slowly tries to tame his aura, wild steamy tongues turning to puffy clouds, lightning to soothing touches and it seems to help, because after a few moments Hyunjin’s eyes close, only to focus on Seungmin’s face.

“Hyunjin, Hyunjinnie, my princess…”, Seungmin is still praying to her, his face lighting up with a smile when the human blushes at her pet name. “You can hear me again, little one? Back with me?”, a nod. “Good girl, can you talk?”, Hyunjin shakes her head fast enough, Seungmin is scared she might give herself whiplash. “Okay, baby, that’s fine. Did this happen before? You ever got so overwhelmed you couldn’t speak?”, she shakes her head again, this time more reluctantly. “Do you feel good? Want to continue?”

Hyunjin nods wildly and not only that, she brings her hips forward, a desperate attempt to get Seungmin inside of her, but only nudging against him ever so slightly. It seems to be enough for her to find her voice again, because even the small touch makes her mewl, back arching and voice breaking at the end. She seems to gain more back than only her voice, head clearing up somewhat through the thick haze of _Seungmin_.

“C-c-c…” She tries, groaning frustratedly at the end, because she just can’t seem to talk anymore, lost every sense of it in her pleasure. Seungmin can’t per se read her thoughts, only taste feelings and emotions and he suddenly gets overwhelmed with a wave of worry from Hyunjin, flickering in her gaze on his erection and the way she clenches shut around nothingness as if to protect herself from something.

It takes a second for the demon to combine it all, _protect_ in the end being the keyword as he realizes and looks up again, trying to push his energy from pure devouring lust to a calming flame to ease Hyunjin’s anxiety.

“Are you worrying about protection?”, he asks, gaining the tiniest nod from Hyunjin. It makes Seungmin proud in a weird way, that Hyunjin thinks of such things despite the incredible heat of the situation. “Like I said, I’m a succubus, I can’t impregnate people. The other nice thing about being a demon is that puny human’s diseases can’t be transmitted to me, so I’m as clean as can be, just like you, my delicious little thing.”

Seungmin chuckles at the short hint of offense on Hyunjin’s face as he insults her race, quickly replaced with a blushy embarrassment from worrying about such things in the claws of a _demon_. Of course they wouldn’t have any problems of that sort. She is glad for the safety of knowing that _she_ apparently is clean as well, another thing Hyunjin hopes she’ll remember after this to ask Seungmin about.

With a strength of ten horses, all of her thoughts are blown away again as she feels that familiar hazy mist engulf her, Seungmin’s whole being switching from careful and soothing to enticing and dangerous.

When he leans over Hyunjin, one hand beside her head and his breath hot on her face, much like it would be if he would be inside of her, she can’t help but whine, desperate and sweet. The only thing close to urging the demon on, she can utter.

“Want me inside you now? Finally fill you up like a good girl?” Seungmin whispers darkly, cooing at the way Hyunjin’s whole body shudders underneath him and a small sob leaves her swollen lips.

“S-Seu… _min_ …” She chokes out, barely a version of her friend’s name because words hurt in that safe cloud she finds herself in. They break the spell and take up too much space where she wants every pore of her body to be concentrated on Seungmin pressing against her.

“ _Shhh_ , princess. Don’t worry, I’m here.”, Seungmin reassures her, bringing one hand between them to grab his oversensitive cock and slowly push it against Hyunjin, running his length up and down between her folds to coat himself in her delicious wetness. He only stops when she is trembling underneath him like a leaf, his very tip pressed to her entrance so that he can lightly feel each and every contraction of her muscles. “I’m going to make it all better, Jinnie.”

And with that Seungmin presses in, pure wet tightness engulfing and pulling him in deeper and deeper, intoxicating warmth spreading around him and making way for his all until there is nowhere to go, his hips flush against Hyunjin’s damp skin and he fits _perfectly_. Made for each other in the truest sense.

Finally, Hyunjin cries out louder, voicing Seungmin’s every thought because as much as he can feel her tightness clenching around him, he can feel _himself_ being spread open in her being. Somewhere unreachable in his soul does he feel what Hyunjin feels and it is nearly too much, something a human definitely couldn’t stand. What a fortunate thing that Seungmin isn’t human.

Hyunjin can’t help from closing her legs behind Seungmin’s back when he is finally fully sheathed. Her eyes are long closed from pleasure, wetness pricking at the edges, because finally she feels full again, full with a real cock instead of her cheap toys and it isn’t just anyone’s, it’s _Seungmin’s_. The demon’s, who is her best friend and she could not think of anyone better to finally make her feel whole again.

It only gets better when he moves, something in his size pulling and pushing all the right things, the lack of a condom making them feel so close, hot and tight like one. Seungmin is perfect inside her, filling her up completely but not crushing her cervix, spreading her beyond known levels but not ripping her apart.

Either his years of skill or the way his dick is just shaped so _differently_ makes him brush against her spot with the first real thrust, pulling out to barely his tip and when he thrusts back in with that demonic force, rubbing against her so perfectly, Hyunjin truly finds her voice again. She is loud and unapologetic, nonsensical and probably not graceful in the way moans and guttural whines, sobs and mewls spill out, curses of Seungmin’s name or at least a variation of it. She just wishes she could truly yell for him, tell him how good it feels in the rhythm of each of his thrusts.

They aren’t forcedly fast, just deep and hard, painful in the way they reverberate throughout Hyunjin’s core and leave her breathless, chunks of Seungmin’s name choked out of her throat and she just wishes she could let go and say that easier word that burns on her tongue.

Seungmin has never felt like this before, taking and giving at the same time, feeling more than just being energized and fed and satisfied, feeling truly _human_ in Hyunjin’s skin. Each drag in and out of her heat have him moan louder and louder, praises and curses and pet names spilling over as he tries to grab onto the blanket for dear life.

Despite never having had it before, he can feel something build, something different than a normal orgasm splicing in his groin, tightening his muscles and at some point, snapping. It feels much slower, a lot more deliberate and sickly sweet at the very base of his length, above where it usual pulls just ever so slightly. His knot is growing already.

Hyunjin, who didn’t get a chance to even realize before, feels it too. How it is slowly growing each time Seungmin pushes in to the halt, each time his skin slaps loudly against hers it tugs at her rim, pushing her even more beyond limits she thought were possible.

With a choked sob the first tear rolls out from closed lids. Seungmin has a knot. That impossible dream of hers she had since she was a teenager, awakened by an embarrassing fanfiction of her favourite series. That idea of being used and filled by it, more than just from a toy, that just seemed so unrealistic. It is now happening in a way that has her feel taught in all the right places.

“S-min…” She chokes out, wishing she could thank him for answering her prayers. Wishing she could give at least a fraction of that back what she is feeling. Quite the opposite seems to have happened, because Seungmin _pauses_ his movements, coming to a halt deep inside of her so that she can feel him throb and grow against her walls, slowly but surely spreading her open.

“J-Jinnie,”, Seungmin moans, voice equally broken and it shows just how much it affects him too, how gone he is with all of Hyunjin around him and filling him up. “You can… can call me alpha, I know you want to.”

More tears spill over when Hyunjin’s eyes fly open, a shocked look being directed at Seungmin just begging to tell him how he could possibly know _that_. That fictional thought of alpha’s and omega’s that Hyunjin so dearly wishes she could be a part of.

“Oh, babygirl, I know everything.”, It’s an overexaggeration by a long shot, but paired with a smirk it has Hyunjin tighten so deliciously around him, Seungmin doesn’t care about his lie. “It’s okay for me, you can call me alpha. You’re my dumb little pup after all and only alpha can fuck you how you deserve it.”

With a snap of his hips, Seungmin sets a different pace, less deep and more a frantic chase for release and it only takes a few plows for Hyunjin to feel her core tighten, each grind against her spot and push to open her up for Seungmin’s knot so much for her spent body, drained of all energy in the truest of ways.

“A-alpha,”, she sobs when she finally comes, arching against Seungmin and pulling him even closer, his hips now barely moving inside of Hyunjin. “Alpha- _a_ , alpha, _alpha_!”

She chants the word with broken sobs retching through her, tears running and running, and it is the only word she can fathom, the only word that feels _right_ with Seungmin grinding into her with his knot.

“You’re so tight, princess, so perfect for alpha.” Seungmin feels close to sobbing too, Hyunjin’s orgasm rippling through him in a phantom touch, tickling his insides and making him feel spent but his body is screaming the opposite, as if the knot is truly begging him to fuck and take and thrust until he can fill Hyunjin up to the brim. It is excruciating, exhausting, better than anything else.

Hyunjin brings her hands up from where they are fisted into the duvet, to grip into Seungmin’s back moving and pulling, urging him on to move, because her body is screaming from oversensitivity, but also for something else, for so much that she won’t be able to take, so it can only spill out and leak.

It takes a lot to spur his body on again. Seungmin’s succubus soul is alive, completely filled up and energetic, but his human vessel is done, dripping sweat and muscles trembling as he tries to fulfill Hyunjin’s needs, whilst simultaneously being crushed by her own tiredness. He somehow pushes himself up, motivated by nails digging into his skin and wet moans filling his ears.

It’s frantic, sporadic even, in the way that Seungmin can’t find a rhythm, can’t concentrate on one length or stroke or pace because it all feels too much, Hyunjin tight around his length already but nearly suffocating where his knot is filling up. With the way he can feel that delicious soreness of Hyunjin it doesn’t take long until Seungmin isn’t able to move anymore, to big for thrusting, so he pushes in to the halt under a pained hiss from Hyunjin, locked together like one body.

Neither of them have ever felt anything like it before, bodies aligned with no way to even part, no way to move from the heat of the other because they are _locked in place_. Seungmin’s knot barely fitting inside and Hyunjin shut tight around him.

Like this, it only takes an accidental clench from Hyunjin’s walls for Seungmin to explode, the string holding himself together finally snapping as he comes and comes and comes, waves of his pleasure hitting Hyunjin in the way of his aura basically exploding all around them and his cum running into her spurt after spurt. It stretches her even more, the amount so unnatural, but it feels better than anything Hyunjin’s ever felt before, the way it forces her walls to open up the slightest bit wider, liquid somehow leaking its way around the knot in a tiny dribble. She never wants it to end.

It doesn’t, not for a while at least. A steady trickle dribbling down between her legs and staining her duvet beyond belief until it finally cedes, a more than generous amount still locked inside of her by Seungmin who is just beginning to shrink, well tied to her for a while.

Hyunjin feels like she can finally breathe air again, the demon’s aura not overpowering anymore, and it feels equally relieving as well as freezing, despite Seungmin’s hot body heaving on top of her. It’s as if with his powers, some of Hyunjin’s energy left too, making her feel isolated and lonelier than before.

In the last waves of their pact intact, Seungmin can feel her unease, sorrow even with the way his guts twist up from Hyunjin’s emotions. So he latches onto her skin where he is panting in the cleft of her shoulder, pecking his way up her neck until she is giggling from the ticklish sensation. He only pushes himself onto his elbows then, looking at his friends ruined face that makes him feel proud and strong, because this was his work.

“Do you want me to go away?” It’s barely a whisper, Seungmin’s throat feels raw from lots of moaning on both of their behalves, so he doesn’t dare to manage more. It fits the mood too, this in between feeling of just having had amazing sex and then realizing with whom exactly. With his best friend. Maybe staying would be too much. And despite a knot currently locking them together Seungmin could always force himself to change to something smaller, able to pull out.

Hyunjin however, quickly shakes her head, stopping the gnawing on her swollen lips. “Please don’t, you’re quite literally the only thing holding me together right now.” She reaches out then, lacing her fingers through Seungmin’s now-messy hair, trying to untangle a few strands.

“Was this okay?”, Because with his hunger and the pact gone, Seungmin worries if fucking your best friend is okay for _his_ best friend. “This won’t ruin our friendship, right?”

As always, she proves him wrong, smiling down at him in that same manner that was there before, not a hint of pain in her eyes or a tremble on her lips. “If anything, we’re even closer now. I think I could feel you in my head earlier. Before I went all…” She blushes again, pouting her lips out in hopes Seungmin would know what she means, as he did so often that evening.

“Dumb? Fucked stupid from alpha’s cock?” Seungmin doesn’t even try to avoid the light smack delivered to his arm, Hyunjin hiding her face away to the side, pressing it down in her black curls and the pillow.

“I would’ve said _nonverbal_ , but yours is true too.”, she mumbles, hiding herself away further when Seungmin moves to chase her face. “So, you really know everything now?” She whispers when he finally catches her, a finger to the tip of her nose and a soft peck on her lips after her words come out.

“Not _everything_. Just all the sexual stuff.”, Seungmin giggles again when Hyunjin yelps lightly with realization. “How you want to be filled like you are right now, call me alpha, how you want to be spread open and open and _open_ , gaping and leaking with someone’s cum. I know that you have very sensitive nipples and they hurt in the bad way, so I didn’t really touch you there. I know how you wish you would like it up the ass, so three people can have a go with you at the same time, one for each hole… Maybe I should call a few of my friends over, huh? I know just the perfect one for you, all abs and strength an-“

“Shut up, Seungmin!” Hyunjin’s body is _spent_ , more than ever before, but as he keeps laying out her secret desires, she can feel herself somehow get hot and bothered again, aching around Seungmin for more despite being in no state to take that.

“Jinnie, don’t take my next words the wrong way please.” Seungmin can feel how he is slowly going flaccid, knot soon gone down enough to pull out, so he wants to get it out as long as they are still connected like this. Even if their pact tying their minds together isn’t there anymore, the demon can feel Hyunjin stiffen up with worry, brows knitting together again, so he makes sure to smile soothingly, trying to show her that it’s not something bad that he needs to tell her.

“O-okay?” She can feel it too now, how that satisfying feeling of being so _full_ is slowly shrinking and only barely pressing against her. How more of Seungmin’s release is running out of her gaping entrance despite of him being still inside. It feels just like she had imagined it, better even, sweet to her skin feeling so raw. She doesn’t think normal sex will work for her ever again.

“I love you.”, Seungmin says then, voice shaky as he bites the inside of his cheek in a wait for Hyunjin’s reaction. He’s sure she will look shocked, betrayed maybe, or simply confused, but nothing of it comes. Instead she just smiles that blinding smile of hers that makes Seungmin’s whole world stop spinning for a moment. “Not in the way a partner would, or a husband, I love you as my best friend.”, She laughs, tears welling up in her eyes from happiness and Seungmin can breathe again, because he knows that she understands. “My best friend who I want to keep fucking until she can’t stand me anymore.”

“I love you too, Minnie. In the same way.”, Her laugh is the forbidden sound of heaven, tempting Seungmin to believe in salvation. “I love you so much and you can keep fucking me forever, I’ll never grow tired of you.”

“Promise?” Seungmin is supposed to be the demon seducing humans for his own needs, but he has found his mundane nemesis that turns the game around and he knows he will never want someone else again.

Hyunjin props herself up on her elbows and rubs her nose against Seungmin’s before moving even closer. They kiss in a way neither of them have ever been kissed before. Pure emotion and electricity in the heat between them.

Mumbled against swollen lips, Hyunjin pledges her vow. “I promise.”

**Author's Note:**

> Thank you so much for reading! 
> 
> If you liked this fic, please leave kudos and comments so I don't feel like a failure because I put hours into writing it... 
> 
> If you have any questions or just want to follow my horny ass on twitter, please do. It's the same handle as here @ninchannie. 
> 
> Until next time...
> 
> ~N


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